Prototyping is typically used during product development to verify design concepts and to facilitate advance testing. A prototype must have structural characteristics sufficiently close to the desired product to permit a realistic prediction of actual product performance. Prototyping sheet metal formed parts can be expensive both in capital outlay and in development time. The manufacturing operations must first be defined for such parts and then the parts must be painstakingly produced by conventional cutting or forming processes, often requiring skilled labor, considerable time and expense.
Any number of sheet metal forming processes may be utilized to shape sheet metal blanks into desired parts. These sheet metal forming processes include, but are not limited to, simple hydraulic press forming, stretch forming, deep drawing, and rubber pad forming operations (e.g., Guerin, Verson-Wheelon, Marform, Hydroform, and Hydrodynamic processes) . The forming processes utilize formblocks or dies. Forces are exerted on the sheet metal blanks which are pressed against the formblocks whereby the sheet metal is forced to conform to the shape of the formblock.
Development of the formblocks or dies used in the forming process is costly both in terms of expense and time, especially when considering the number of design iterations and the relatively small prototype volumes. As such, increasing the efficiency of manufacturing prototypes or small batches of sheet metal parts is highly desirable.
It is well known that stereolithography may be utilized to create three-dimensional objects, such as prototype parts. Stereolithography conventionally calls for a laser beam to be directed by computer control into a bath of liquid photopolymer resin. The laser beam is traversed across the liquid resin to selectively cure the resin to form a three-dimensional object through the accumulation of incremental layers of cured resin. Thus, this technology melds computer modeling techniques with the actual creation of three-dimensional models.
A significant shortcoming of stereolithographically produced resin models, however, is that the resins employed have considerably less strength than the strength of materials designated for the final part (e.g., steel, aluminum or plastic). As such, parts produced using stereolithography have been limited to visualization models for verification of production intent, rather than for functional usage.
A technique used to strengthen stereolithographically produce resin part is disclosed U.S. Pat. No. 5,616,293 to Ashtiani-Zarandi et al. The patent discloses a stereolithography build technique using internal interconnected support members.
Accordingly, there is a need in the art for a method to increase the efficiency to manufacture sheet metal parts, especially prototypes or small batches of parts.